A dozen other researchers from the United States and Canada crouched around the young seal, carefully taking blood and hair samples as Moxley, a doctoral student at Duke University, poured white glue onto the back of the seal’s neck.

He grabbed a popsicle stick stashed in a strap around his tousled hair and used it to methodically dab glue into the seal’s fur.

What followed was crucial — and historic.

He placed a high-tech monitor on the seal that will record a wealth of information about the marine mammal’s daily life over the next several months and transmit the data back to a team of researchers. It is the first time researchers have tagged and tracked adult gray seals in the United States, according to the researchers.

The team had 10 minutes before the glue hardened, and they needed to keep the powerful animal still. But there was a problem. During the commotion, glue had gotten onto the device’s sensors, threatening to scuttle the whole project.

“Who has a scalpel?” yelled David Johnston, a research scientist from Duke’s Marine Lab. “We need a scalpel.”

Moxley began cleaning off the sensors with the blade tip. After a few tense minutes, the device was cleaned, and the researchers backed away.

Flipper by flipper, it waddled back into Chatham Harbor and disappeared into the water.

The team’s first day was about half over, and researchers had tagged their second seal.

“We don’t get access to animals like this very often, so you have to keep calm to perform the task,” Moxley said after the seal returned to the water. “This is important for science.”

He is one of nearly two dozen scientists from several major marine institutions who will be zooming around Cape Cod this weekend as part of the first-ever attempt to study the way the ubiquitous gray seal interacts with the local environment.

The gray seals’ population in the Northeast has exploded in recent years, earning the ire of local fishermen who can lose valuable catches to the ravenous mammals. The seals also lure great white sharks to the beaches of Cape Cod.

Scientists do not know much about the region’s gray seal population — how large it is, for example, or where the seals spend most of their time, said Gordon Waring, a seal specialist with the National Oceanic and Atmospheric Administration and the project’s lead scientist.

Researchers will analyze blood, blubber, and whiskers to unlock the secrets of seal life, including what they eat.

The device glued to the head will use cellphone towers to send location, the depth of seal dives, and water temperature.

“When you pare it all down, it’s an iPhone with a really big battery,” said Johnston. “We are going to get some really amazing glimpses into the lives of the animals.”

The group is composed of researchers from the National Oceanic and Atmospheric Administration’s Northeast Fisheries Science Center in Woods Hole, the Provincetown Center for Coastal Studies, and Canada’s Department of Fisheries and Oceans, among others.

They plan to tag nine gray seals and collect biological samples from up to 30 seals through Monday.

The batteries on the cellular tags will last long enough to transmit data for seven to nine months.

The project is a rare in its scope, said Robert DiGiovanni, a biologist and director of the Riverhead Foundation for Marine Research and Preservation.

His foundation, with headquarters on New York’s Long Island, and the Northeast Fisheries Science Center have been jointly researching seal species in the Northeast but only recently received funding for gray seal research.

A smile crept across DiGiovanni’s face as he watched the second seal return to the water.